Clutched driving means for tools



Aug. 19, 1952 R. E. GEARHART 2,607,253

CL-UTCHED DRIVING MEANS FOR TOOLS Filed may 23, 1949 2 SHEETSQSHEET 1 i a v w /i 1 a Patented Aug. 19, 1952 UNITED STA PATENT OFFICE.

mce wa ing non 'rooLs I Roy E. -Gear'h-art, Kansas City, Mo.-, assignor of one-half'to'fiharles Hose, Kansas City, Mo.

'Appli'cationMay 23, 1949, Serial No. 94,885

This invention relatesto'new' anduseful improvementsinclutch tools,- and has particular reference to tools of the classincluding' wrenches and screw drivers.

In using toolssuch as wrenches or screw drivers it isoftendesirable to turn an-ob'ject such as a nut or bolt or screw in onedirection only while turning thetoolreciprocally, Without disengagingv the tool from the object being turned. This object is ordinarily accomplished by ratchet wrenches or screw drivers;- "The principal object of theprese'nt invention "is the provision of a tool of this-class having numerous advantages over the usual ratchettype tools.

Another object is theprovi's'ion of a-to'ol of theclass described having'a manually operable driver I handle, and a work" engaging'member, cooperating clutch members carried respectively by said handle and'work engagingmember,- said clutch members being so relatedthat a slight relative movement of said handle'an'd work engaging member in a direction transverse tothe direction of'rotation ofthe tool'wil-l cause 'an initial engagement of said clutch members,- and means operable when 1 said handle as turned in either direction to force said--clutch members into full engagement. 1

A further object-is the provision, in a'too'l of the class described','-'ot means adapting the tool to rotate objects in either direction without :the operation of external switching-levers or the'like:

A still further object is the provision'in "a" tool of the character described, of a pair of circular toothed clutch members adapted-to mesh together aroundtheir entireperipheries, whereby the clutch members will function eificiently even though a'considerable number'or the teeth are broken ordamaged. 7 I

Other objects are simplicity and economy-of construction; ease and convenience of "operation; durability, adaptability to be' used 'in tools of very; small size, and adaptability to beusedin' toolsof various types.

With these objects in view, as "well as other objects which will appear "in- 'thecourse *ofthe specification, reference'will b'e-h'a d to the draw-' ing, wherein:

Figure 1 'is' a side elevation of a clutch wrench embodying the present invention, with parts broken away. I

Fig. 2 is an edge'view'rofthewrenchshown in'Fig. 1. I

Fig; 3 is an enlarged fragmentary section taken on li'neIII-III of Fig; 2, with".the wrench socket member omitted.

8 -Claims'. (Cl. 81-58) Fig. 4 is a" section taken on line IVIV of Fig; 3.

Fig. 5 is an'irregular section'taken on line V-'Vof Fig. 3, showing a face View of-the operating cams fixed in the body member;

Fig. 6- is an irregular section also taken on line V-V of'Fig. 3, but'looking in the opposite direction, showing a face view of'the cams and stops" carried by the floating clutch member.

Fig; 7 'is a fragmentarysection taken on line VII-VII of Fig; 6; showing the toothedclutch members in their" normal, disengaged relationship. I

Fig; 8 is a view similar'to 'Fig. 7, showing the clutch members brought 'into' partial engagement by axial movement of'the faceplate;

Fig. 9 is a view similartojFig. 7, showing-the clutch members brought into full engagement by. the action of the operating'cams:

Fig; 10' is a side elevation of a screw driver embodying the present invention. I

Fig. 11 is an enlarged fragmentary section takenon line XI'XI of Fig. 10; I I

Like reference numerals apply to similar'parts throughout'the several views, and in thewrench shown in Figs; 1.13019; thenumera'l'2- applies to a hollow, cylindrical body member closed at one end by wall 4 'and "having a radially extending handle 6- welded or otherwise rigidl'yf' attached thereto. A-flat cylindrical face plate-8 is-carried for rotation and axial sliding movement "in the open end portionof body member-2; The portion of said face-memberis provided with a radial flange 10- adapted to abut against body-member 2 to limit the inward sliding movement of the faceplate. Said face plate'is formed to present an outwardly-extending axial stem 12, preferablysquare'in cross-section, adapted to fit into a correspondingly shaped hole 14 formed man ordinarywrench socket member It: Saidsocket member is retained on said stemby a detent'ball l8 embedded" in arecess 20 formed in'stemlz and urged outwardly'by' a spring 22 carried'in saidprecess. Sai'd'ball is adapted to engage a recess 24 formed in the 'wall of hole I4. I Socket member [6 has a non-circular'socket 26 formed in itsouter end for engaging Lniits', -bolt heads, and the like. Said socket members of course are usuallyv sold in sets, having. socketsiof 'gradu ated sizes and difierent shapes. Thistype of socket, and its mounting, is commonYand-no claim is, made specifically thereto.-

A plurality of teeth 28 are formedon the-inner surface .30 of face plate 8, sa'id teeth beingequally spaced about the periphery of said face plate and I A screw 36 is threaded axially into the free end of said shank. The head 38 is disposed rotatably in a countersunk hole 48 formed in the outer surface of wall 4. Said head abuts against the s end of shank 82, and also against an outwardly facing shoulder 42, formed at the bottom of hole 40, thereby limiting the outward sliding move ment of face plate 8. It will be noted that flange I8 is normally spaced apart from body member 2, the clearance 44 therebetween permitting a very limited axial movement of the face plate in the body member.

Welded or otherwise fixed in body member 2 within the annular space between bearing tube 34 and the cylindrical wall of said body member, are a pair of like operating cams 46, best shown in Figs. 5, 7, 8 and 9. Said cams are disposed in diametrically opposite sides of the housing, and each has substantially the shape of a segment of a fiat annular ring. The outer surface of each of said cams, or the lower surface as viewed in Figs. '7, 8, and 9, is formed to present a substantially V-shaped groove 48 disposed radially to the body member. Said cam is formed to present flat dwell surfaces 58 adjacent each side of said groove. and 54 of said cams are radially disposed and parallel to the axis of the body member and serve as stops as hereinafter described.

A floating clutch member 56 is carried for rotation and axial sliding movement on shank 32 between face plate 8 and body wall 4. Said clutch member has the form of a flat gear having radially projecting teeth 58 equally spaced around the periphery thereof. Said teeth are adapted to mesh with teeth 28 'of face plate 8, as said clutch member is moved axially toward said face plate along shank 32. On the surface of clutch member 56 adjacent body wall 4 are formed a pair of like cams 60. Said cams are disposed on diametricallyopposite sides of the axis of the clutch member, and are substantially V-shaped in order to mesh with V-grooves 48 of operating cams 46, as best shownin Figs. 7 and 8. Each of cams 68 is provided at its apex with a' flat dwell surface 62. A pair of stop members 64 are also formed on clutch member 56. Said stop members are segments of annular rings, and are disposed at diametrically opposite sides of the clutch member, ninety degrees removed from cams 60, and are adapted to project between operating cams 46. The end surfaces 66 and 68 of said stop members are disposed radially'and parallel with the axis of the body member, and cooperate with surfaces 52 and 54 of operating cams 46 as hereinafter described. A helical spring 69 is disposed about shank 32, bearing at one end in a circular groove 10 formed in clutch member 56, and at its opposite end in a similar groove 12 formed in inner surface 38 of face plate 8. Said spring functions to urge face plate 8 and clutch member 56 apart to keep teeth 58 and teeth 28 out of engagement and to urge face plate 8 to the outer limit of its axial movement.

The operation of the wrench is substantially as follows: .When socket member I 6 is positioned over a nut or the like which is to be turned, face The end surfaces 52 plate 8 is in effect directly coupled to the nut. Body member 2, however, can be freely rotated in either direction without turning said face plate, as long as the partshave the relative positions shown in Figs. 3 and 8 since clutch teeth 28 and 58 are out of engagement. Clutch member 56, by reason of the engagement of cams 68 in cams 46, turns with the body member. The operator, whileturning the body member in the direction desired by means of handle 6 exerts a slight pressure axially on the body member, thereby forcing face plate 8 inwardly relative to the body member, against the pressure of spring 68, until flange ID of said face plate strikes the body member. Since the clearance 44 between said flange and 'body member is slightly greater than the clearance between teeth 28 and teeth 58, this relative axial movement causes a slight meshing of said teeth, as clearly shown in Fig. .8. Since there is a substantially large number of teeth in the circumference of the toothed members, they may also mesh at numerous points in each revolution, and there will hence be very little lost motion before said meshing occurs.

Clutch member 56 is thereby secured against rotation relative to face plate 8. Further rotation of body member 2 by the operator causes operating cams 46 to force cam 68 and clutch member 56 axially toward faceplate 8, thereby moving teeth 58 of said clutch member into full engagement with teeth 28 of said face plate, as shown in Fig. 9. When earns 68 have been forced all the way out of grooves 48 of cams 46 ,dw ells 62 of cam 68 contacts one of dwells 58 of cam 46, thereby securing the clutch teeth in the engaged position. At the same time, cams 46 strike stops 64, whereby rotation of body member 2 relative to clutch member 58 is arrested. For example, when the body member is turned clockwise as viewed in Fig. 6, stop surfaces 56 of cams 46 strike stop surfaces 66 of stops 64. If the body member were turned in a counterclockwise direction, surfaces 54 of cams 46 would strike surfaces 68 of stops 64. p

Any torque exerted'on handle 6 by the operator will be transmitted directly to clutch member 56 by cams 46, from said clutch-member to face plate 8 by'means of teeth 58 and 2 8, and from said face plate to socket member l6-by means of stem [2. Reversingthemovement of handle 46 will move cam groove 48 over cams 68, whereupon spring 68 will separate clutch member 56 from teeth 28 of the face plate, to permit free reverse rotation of the body member.

It will be noted in Fig. 9 that cams 46 do not push clutch member 56 tightly against face plate 8. There isa slight axial clearance between these members even when these respective teeth are engaged. This removes any axial stress from assembly screw 36, and prevents a y, tendency for said screw to become loosened during normal operation. It will be noted also that since no substantial torque can be transmitted .from clutch member 56 to face plate'8' until cams 46 strike stops 64, teeth 28 and 58 are fully. engaged before they are required to transmit the full load being applied to the tool. This permits easy engagement of the teeth, and tends to prevent tooth breakage and damage.

Figs. 10 and 11 show a screw driver embodying the present invention. Body member 14 of the screw driver, which corresponds to body member 2 of the wrench, is substantially similar to body member 2 except that it is provided with a rearwardly extending circular wall 16 which Thus it is apparent that a clutch-type tool having several advantages ,has been produced. It will .function in the mannerof aratchet-type tool to turn work in one direction only as the tool itself .is reciprocated, and may be reversed to turn the work in the opposite direction without, opera.- tionofareversing lever or the like. By positioning the parts so that dwells 62 of earns 60 engage dwells 5!) of cams.46,-the clutch may be secured in'the engaged position to turn work in either direction. Because of the multiple tooth engagement of the. clutch, it, will continue to function efiloientlyeven after a considerable number of. teeth are broken. The clutch mechanism is, peculiarly adapted for use in tools of very small diameter, hence providing a tool adapted for use in inaccessible, cramped quarters.

Although I have disclosed specific embodiments of my invention, it is apparent that many minor modifications of construction could be made without departing from the spirit of the inventions I -WhatIclaim is: a

l. A.c1utch tool comprising a body member, a handle by means of which said body member may; be rotated, a first toothed clutch member carried for rotational and axial movement by said body member, a work engaging member fixed to said clutch member, a second toothed clutch member carried for axial and limited rotational movement by said body member, said clutch members being adapted to be partially engaged by axial movement of said first clutch member, and cooperating cams carried respectively by said body member and said second clutch member, whereby said second clutch member is moved axially into full engagement with said first clutch member, said cams having dwells whereby said clutch members may be retained in the engaged position.

2, A clutch tool comprising a body member, a handle by means of which said body member may be rotated, at first toothed clutch member carried for rotational and axial movement by said body member, a work engaging member fixed to said clutch member, a second toothed clutch member carried for axial and rotational movement by said body member, said clutch members being adapted to be partially engaged by axial movement of said first clutch member, means operable by the relative rotational movement of said body member and said second clutch member axially into full engagement with said first clutch member, and stops adapted to arrest the relative rotation between said second clutch member and ber carried for "axial and rotational movement by said body member, said: clutchmembersfbeing adapted to bepartially engaged by axial move: ment of said first clutchmember, cooperat ing camsfixed respectivelylto said bodymemher and said second clutch member, whereby said second clutch member is moved axially into full engagement with said first clutch member when said body member is rotated in either direction relative to said second clutch member, said cams having dwells'whereby said clutch members may beretained in the engaged position, and stops for arresting the relative rotation. of saidv body memberandsaidsecond clutchmember when said clutch members are fully engaged. .u;

4. A clutch tool comprising a .body member, a handle. by means of which saidbody' member may be rotated, a first toothed clutch member carried for rotational and axial movement by said body member, a work engaging member fixed to said clutch member,.a second toothed clutch member carried for axial and rotational movement by said body member, said. clutch members being adapted to be partially engaged by axial movement of said first-clutch member, means operable by the. relative rotational. movement ofsaid body member and said second clutch mem-; ber axially into. fullengagement with said" first clutch member, and stops-adapted to arrest the relative .rotation between said second clutch member and ,saidlbody member when-said clutch members, are fully engaged, the parts being so proportioned as to provide a slight axial clear-. ance between, said firstand second clutch members when the teeth of said clutch'members are.

fully engaged. v

5. A- clutch tool eomprising-ahollow cylindrical body member, a handle by means of which said body member may be axially rotated, a first clutch member carried for rotation in said body.

member and adapted to be manually moved axially in said body member, stops limiting the axial movement of said clutch member, a work engaging member fixed to said clutch member, a second clutch member carried for rotational and limited axial movement in said body member, said clutch members having matching peripheral teeth adapted to be engaged by relative axial movement of said clutch members, resilient means normally holding said clutch members apart, said clutch members being adapted to be partially engaged by manually moving said first clutch member to the inner limit of its axial travel, and cooperating cams carried respectively by said body member and said second clutch member whereby relative rotation of said members in either direction will move said second clutch member axially into full engagement with said first clutch member.

6. A clutch tool comprising a hollow cylindrical body member, a handle by means of which said body member may be axially rotated, a first clutch member carried for rotation in said body member and adapted to be manually moved axially in said body member, stops limiting the axial movement of said clutch member, a work engaging member fixed to said clutch member, a second clutch member carried for rotational and limited axial movement in said body member, said clutch members having matching peripheral teeth adapted to be engaged by relative axial movement of said clutch members, a spring disposed between said clutch members and adapted normally to maintain said clutch members out of engagement and to maintain said first clutch member at the outerlimit of its axial travel, said clutch members being adapted to be partially engaged by manually moving said first clutch member to the inner limit of its axial travel, and cooperating cams carried respectively by said body member and said second clutch member, whereby relative rotation of said members in either direction will move said second clutch member axially into full engagement with said first clutch member.

7. A clutch tool comprising a hollow cylindrical body member, a handle by means of which said body member may be axially rotated, a first clutch member carried for rotation in said body member and adapted to be manually moved axially in said body member, stops limiting the axial movement of said clutch member, a work engaging member fixed to said clutch member, a second clutch member carried for rotational and axial movement in said body member, said clutch members having matching peripheral teeth adapted to be engaged by relative axial movement of said clutch members, resilient means normally holding said clutch members apart, said clutch members being adapted to be partially engaged by manually moving said first clutch member to the inner limit of its axial travel, cooperating cams carried respectively by said body member and said second clutch member, whereby relative rotation of said members in either direction will move said second clutch members axially into full engagement with said first clutch member, and stops for arresting the relative rotation of said body member and said second clutch member when said clutch members are fully engaged.

8. A clutch tool comprising a hollow cylindrical body member, a handle by means of which said body member may be axially rotated, a first clutch member carried for rotation in said body member and adapted to be manually moved axially in said body member, stops limiting the axial movement of said clutch member, a work engaging member fixed to said clutch member, a secondclutch member carried for'rotational and axial movement in said body member, said clutch members having matching peripheral teeth adapted to be engaged by relative-axial movement of said .clutch members, resilient means normally holding said clutch.members apart, said clutch members being adapted to be partially engaged by manually moving said first clutch member to the inner limit of its axial travel, cooperating camslcarried respectively by said body member and said second clutch member, whereby relativerotation of said members in either direction will move said second clutch members axially into full engagement with said first clutch member, and stops for arrestingthe relative rotation of said body memberand said second clutch member when said clutch members are fully engaged, said cooperating cams having dwells which come into matching relation as said stops become operative, whereby said clutch members are secured in the engaged position. 1

ROY E. GEARHART.

REFERENCES CITED The following references are of record in th file of this patent:

UNITED STATES PATENTS 7 Date Number Name 1,484,192 Ringquist Feb. 19, 1924 1,643,860 Shedd Sept. 27, 1927 2,350,958 Bryant June 6, 1944 2,351,996 Morgan June 20, 1944 2,390,792 Jespersen Dec. 11, 1945 

